Our iPolymer Check Valve feature all PTFE wetted surfaces for excellent performance in all high purity applications. Our PTFE design resists chemical corrosion and other elements within a harsh process environments. iPolymer Check Valves are commonly found as backflow preventers in clean processes. They are a simple and ideal device where directional flow control is a must. Depending on the check valve size selected and cracking pressure, some external non-wetted components may include Polypropylene or PVDF. The special internal control spring for 3 psi to 6 psi (nominal 5 psi) cracking pressure is machined virgin PTFE. Whereas, for higher cracking pressures the spring construction is doubled Teflon Coated Stainless Steel precision ground. Please contact us with your special application requirements. Special PEEK, PVDF and Polypro configurations are available upon request.